A Transmission Control Protocol (TCP)-proxy server (also termed TCP Proxy herein) provides a way to reduce objects download or upload time of data between two devices such as a server and a terminal.
The application of a TCP split connection proxy is well known and already often applied. Thus, split TCP is typically used to solve TCP problems with large Round Trip Times (RTTs). A typical system uses Split TCP Performance Enhancing Proxies (PEPs) to improve TCP performance over a link with different characteristics such as a satellite link. Split TCP functions by breaking the end-to-end connection into multiple connections and using different parameters to transfer data across the different legs. The end systems use standard TCP with no modifications, and do not need to know of the existence of the PEPs in between. Split TCP intercepts TCP connections from the end systems and terminates them. This allows the end systems to run unmodified and can overcome some problems with TCP window sizes on the end systems being set too low for satellite communications, see also http://en.wikipedia.org/wiki/Performance_Enhancing_Proxy.
Here it is assumed that the TCP-proxy splits an end-to-end TCP connection. In particular, with today's networks driven by a growth of wireless devices but still accessing internet servers connected over the wired access, the TCP-proxy can be used to split the end-to-end path into two parts—a wireless and wireline link. The gain with the TCP-proxy in this scenario would be from being able to independently handle TCP flows according to bandwidth latency etc. of respective links.
The TCP-proxy terminates a first TCP connection originating from a host in the Internet (or Intranet) and will use a second TCP connection towards the mobile client as shown in FIG. 1. See also EP 1383281, U.S. Pat. No. 7,225,266, and IETF DRAFT, RFC2760, http://tools.ietf.org/html/rfc2760#page-9
In a scenario such as the one illustrated in FIG. 1, a fixed initial window (IWD) size in TCP-proxy can cause that in download case in the internet TCP server IWD is smaller than in the TCP-proxy and then in TCP slow start phase this larger initial window size is useless, especially when latency between proxy and the internet is longer than latency between proxy and User Equipment (UE). Also the other way around, TCP-proxy buffer starts to increase because of shorter latency between proxy and the internet
There is a constant desire to improve the performance in data communications. Hence, there exist a need for new methods and devices providing improved performance in TCP connections involving a TCP proxy server.